Book Image

PostGIS Cookbook - Second Edition

By : Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán
Book Image

PostGIS Cookbook - Second Edition

By: Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán

Overview of this book

PostGIS is a spatial database that integrates the advanced storage and analysis of vector and raster data, and is remarkably flexible and powerful. PostGIS provides support for geographic objects to the PostgreSQL object-relational database and is currently the most popular open source spatial databases. If you want to explore the complete range of PostGIS techniques and expose related extensions, then this book is for you. This book is a comprehensive guide to PostGIS tools and concepts which are required to manage, manipulate, and analyze spatial data in PostGIS. It covers key spatial data manipulation tasks, explaining not only how each task is performed, but also why. It provides practical guidance allowing you to safely take advantage of the advanced technology in PostGIS in order to simplify your spatial database administration tasks. Furthermore, you will learn to take advantage of basic and advanced vector, raster, and routing approaches along with the concepts of data maintenance, optimization, and performance, and will help you to integrate these into a large ecosystem of desktop and web tools. By the end, you will be armed with all the tools and instructions you need to both manage the spatial database system and make better decisions as your project's requirements evolve.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Writing PostGIS vector data with Psycopg


In this recipe, you will use Python combined with Psycopg, the most popular PostgreSQL database library for Python, in order to write some data to PostGIS using the SQL language.

You will write a procedure to import weather data for the most populated US cities. You will import such weather data from http://www.openweatherdata.org/, which is a web service that provides free weather data and a forecast API. The procedure you are going to write will iterate each major USA city and get the actual temperature for it from the closest weather stations using the http://www.openweatherdata.org/ web service API, getting the output in JSON format. (In case you are new to the JSON format, you can find details about it at http://www.json.org/.)

You will also generate a new PostGIS layer with the 10 closest weather stations to each city.

Getting ready

  1. Create a database schema for the recipes in this chapter using the following command:
postgis_cookbook=# CREATE SCHEMA...